I want to bring in NPR's Leila Fadel, who is on the line from Las Vegas this morning. She has been following all the developments. And, Leila, what is the latest in terms of who carried this out and what the authorities know at this point?

LEILA FADEL, BYLINE: Well, at this point, we know that it is a 64-year-old man who was found dead in a hotel room in the Mandalay Bay. Stephen Paddock - he's a man who had no criminal history, had no reason for law enforcement to look at him. He lived in Mesquite, Nev. So it's really unclear why he did this. At this point, they also believe that he acted on his own. They found inside his hotel room upwards of 10 rifles, and they're currently searching his home trying to find out what motivated him but also look for other types of weaponry there.

GREENE: And what - what are you reflecting when you look at this community this morning as you've been spending this morning just talking to people and seeing this?

FADEL: You know, there's not that much time for reflection. This is a city that's reacting. They - there were 22,000 people, some 22,000 people outside when this - when this one gunman opened fire, and he was able to kill upwards of 50 people. So law enforcement, people at hospitals, everybody is reacting; nurses, doctors going to work, journalists working all night, police and first responders going into the - going into a dangerous situation, including off-duty cops, some of whom were killed and are among the - among the dead. This is a city that is not in a moment of reflection but of reaction to make sure everybody's still safe, and they're still identifying victims.

GREENE: NPR's Leila Fadel in Las Vegas this morning. Leila, thanks.

FADEL: Thank you.

GREENE: And NPR justice correspondent Ryan Lucas is with me in the studio. I want to ask you this - there was a Las Vegas Metro Police undersheriff who described this as domestic terrorism. We should be really careful with words like that, right? I mean, the - the local authorities in Las Vegas are saying that this man had no ties to militant groups. This undersheriff's suggesting that if you carry out a mass shooting like this you can call it domestic terrorism. But what questions are federal authorities and local authorities trying to answer right now as they work through what happened here?

RYAN LUCAS, BYLINE: Well, the main question that people are trying to answer is something that Leila alluded to, which is why? Why did Paddock decide to pick up a gun and open fire on a country music festival? This is something that, you know, the FBI is going to help local authorities try to figure out. Attorney General Jeff Sessions has spoken with the FBI director, Christopher Wray. He also spoke with the sheriff for Cark Clowny (ph) - Clark County - excuse me - Joseph Lombardo. He's offered the full support of the FBI, of the Bureau of Alcohol, Tobacco and Firearms and the whole DOJ as the local authorities lead this investigation. And Sessions actually vowed - he said, quote, "we will do everything in our power to get justice for your loved ones." And there's - there's a lot that they have to look into.

GREENE: NPR White House correspondent Scott Horsley is here. Scott, let me just give you the last word here. We heard a very brief, somber statement from President Trump. What is - and I guess he's going to Las Vegas on Wednesday it sounds like, but what did you make of that?

SCOTT HORSLEY, BYLINE: The president talked about this being an event that's joined the country together in sadness, shock and grief. He didn't talk about action. He didn't talk about a response. He offered praise for the police and the paramedics who prevented an even greater loss of life, but he didn't talk about a further response. And I'm struck by what Congresswoman Titus said that you don't want to turn a human tragedy into a political event, she said. But she also said, you know, tomorrow after that - after that period of grief she wants to see some action. She talked about having stood for too many moments of silence and that maybe silence is not the only response here. We certainly heard from some Democrats who want to see action on gun safety measures. However, there was a push for that in 2013 with a Democratic Congress. It stalled. It's hard to imagine it getting traction in a Republican-dominated Congress.

GREENE: All right. NPR White House correspondent Scott Horsley, NPR justice correspondent Ryan Lucas, thank you both. And again we'll be following this story from Las Vegas all morning and throughout the day. Transcript provided by NPR, Copyright NPR.